Nano-CuS powders were synthesized with chemical solution method. XRD and SEM and spectrophotometry were used for characterization of the CuS powders. XRD analysis indicated that tetragonal CuS was the main phase with particle size of 16.2nm and little Cu2S phase was present. Scanning electron microscopy (SEM) analysis revealed that powder was plate like and had very little aspect ratio in morphology. The photo catalytic properties of CuSâ€“Cu2S powders were studied. Methyl orange in water were rapidly decomposed with sunlight irradiation. Benzyl in preliminary production of methyl orange can also be photo-decomposed under sunlight irradiation and can fast be photo decomposed at higher pH condition.